Myocardial Infarction (Heart Attack): Symptoms, Causes & Treatment

Myocardial infarction (heart attack) is a medical emergency that occurs when blood flow to a part of the heart muscle is blocked, usually by a blood clot in one of the coronary arteries. The coronary arteries supply the heart with oxygen and nutrients. When blockage occurs, heart tissue begins to die within minutes if blood flow is not restored quickly.

In Jordan and the Middle East, cardiovascular diseases and heart attacks are the leading cause of death. Heart attacks affect all age groups but are more common after age 40, with higher incidence in men compared to premenopausal women. Treatment success depends heavily on rapid access to emergency medical care, as every minute of delay increases the risk of death and complications.

Heart attacks are classified into two main types: ST-elevation myocardial infarction (STEMI) and non-ST-elevation myocardial infarction (NSTEMI), based on electrocardiogram findings. They are also classified by location (anterior, lateral, inferior) and size. Understanding these distinctions is crucial for determining treatment urgency and potential complications.

Heart attack symptoms may appear suddenly or begin gradually hours or days before the event. It is important to know that symptoms vary between individuals and may be milder in women, the elderly, and those with diabetes. Any unusual chest pain or discomfort warrants immediate emergency call.

• Chest Pain or Severe Pressure: Pain, pressure, or heaviness in the center of the chest lasting several minutes or coming and going intermittently.
• Pain Radiating to Other Areas: Pain spreading to arms (especially left), neck, jaw, shoulders, or back.
• Shortness of Breath: Difficulty breathing with or without chest pain, may occur before chest pain.
• Dizziness and Fainting: Lightheadedness or loss of consciousness, especially in elderly patients.
• Nausea and Vomiting: Nausea or vomiting, particularly in women, elderly, and diabetic patients.
• Cold Sweating: Unusual cold sweating on forehead, face, neck, and chest.
• Severe Fatigue: Unusual tiredness or sudden exhaustion, may occur weeks before in women.
• Heart Palpitations: Feeling of heart skipping beats or irregular heartbeat.
• Anxiety and Sense of Impending Doom: Severe anxiety or feeling of imminent death without obvious cause.
• Heartburn or Indigestion: Pain resembling heartburn or indigestion, particularly in women.
• General Weakness: Unusual weakness in arms or legs.
• Atypical Symptoms in Women and Elderly: Their symptoms may be milder or atypical, delaying diagnosis and treatment.

• Coronary Artery Atherosclerosis: Buildup of cholesterol and fats in artery walls over years, narrowing the passage and potentially blocking blood flow completely.
• Blood Clotting: Formation of a blood clot within the coronary artery due to plaque rupture or irregular heart rhythm.
• Sudden Artery Narrowing: Abrupt spasm of coronary artery muscles, especially in smokers and stressed individuals.
• Embolism from Other Sites: A clot originating from the heart itself (after prior strokes) or other blood vessels reaching the coronary artery.
• Oxygen Supply-Demand Imbalance: Rare cases without complete blockage, such as severe anemia or toxin exposure, causing heart attack.
• Coronary Artery Inflammation: Inflammation of coronary artery walls leading to clot formation or artery narrowing.
• Drug Use: Cocaine and other stimulants cause artery constriction and increase oxygen demand, triggering heart attack.
• Pregnancy and Related Complications: Rarely, heart attacks occur during pregnancy or postpartum due to vascular changes.

• High Blood Pressure: Elevated pressure strains artery walls and accelerates atherosclerosis development.
• High Cholesterol: Elevated LDL cholesterol leads to fat accumulation in artery walls.
• Smoking: Smoking narrows arteries, increases clotting, and reduces blood oxygen levels.
• Obesity: Excess weight raises blood pressure, cholesterol, and insulin resistance.
• Diabetes: Diabetes accelerates atherosclerosis and increases heart attack risk 2-4 fold.
• Physical Inactivity: Sedentary lifestyle contributes to weight gain, high blood pressure, and high cholesterol.
• Family History: Early heart attacks in family members increase genetic risk.
• Psychological Stress and Depression: Chronic mental stress elevates blood pressure and heart rate.
• Age and Sex: Men are more susceptible before age 65; postmenopausal women have similar risk to men.
• Excessive Alcohol Use: High alcohol consumption raises blood pressure and causes arrhythmias.

Rapid and accurate diagnosis of myocardial infarction is critical for saving lives. Diagnosis relies on clinical examination and multiple laboratory and imaging tests. In acute heart attacks, these tests must be performed within minutes to determine attack type and urgency of treatment needed.

• Electrocardiogram (ECG/EKG): First test performed in emergency department within 10 minutes. Shows abnormal electrical waves indicating heart attack. ST elevation (STEMI) requires immediate intervention.
• Cardiac Enzyme Analysis (Troponin and CK-MB): Proteins released from damaged heart cells appearing in blood 2-4 hours after attack. Troponin > 0.04 ng/mL indicates infarction. Measurements repeated every 3 hours.
• CPK Test (Creatine Phosphokinase): Enzyme elevated 3-12 hours after heart attack, remaining high for 48-72 hours. Helps determine attack timing.
• BNP and NT-proBNP Analysis: Proteins indicating acute heart failure or complications. Used to assess attack severity.
• Other Tests: Cholesterol, lipids, glucose, kidney and liver function tests assess risk factors and overall condition.
• Chest X-ray: Performed to exclude other conditions and assess heart size and pulmonary congestion.
• Echocardiography: Ultrasound imaging visualizes heart wall movement, determines lesion location, and assesses ventricular function.
• Coronary Angiography: Gold standard for diagnosing myocardial infarction. Catheter introduced into artery with contrast injection clearly showing arteries and precisely locating blockage.

Medications

• Aspirin: Given immediately upon suspicion of heart attack (500-1000 mg) to prevent clot expansion. Taken daily afterward (75-300 mg) for life.
• Pain Relief (Morphine): Strong painkiller given to relieve severe pain and reduce patient anxiety and heart strain. Dose 2-4 mg every 5-10 minutes as needed.
• Anticoagulants (Heparin): Given by injection rapidly to prevent clot progression. Administered during emergency angioplasty for 24-48 hours.
• Beta-blockers: Reduce blood pressure, heart rate, and oxygen demand. Examples: Metoprolol, Propranolol. Given for life.
• ACE Inhibitors: Preserve heart function and reduce cardiac remodeling after injury. Examples: Enalapril, Lisinopril. Given daily for life.
• ARBs (Angiotensin Receptor Blockers): Alternative to ACE inhibitors if intolerant. Examples: Losartan, Valsartan.
• Statins: Lower cholesterol and prevent atherosclerosis progression. Examples: Atorvastatin, Simvastatin. High dose given immediately after attack.
• Other Antiplatelet Agents: Clopidogrel (Plavix) or Prasugrel given with aspirin for 12 months after stent placement.
• Anti-ischemic Medications: Nitroglycerin sublingual or spray to dilate vessels and relieve chest pain.
• SGLT2 Receptor Inhibitors: New medications protecting the heart and reducing kidney injury. Examples: Dapagliflozin, Empagliflozin.

Procedures

• Emergency Angioplasty (Primary PCI): First-line treatment for acute heart attack. Cardiologist threads catheter through artery (usually femoral) to blockage site, then inflates balloon to open artery. Performed within 90 minutes of diagnosis. Success rate 95%.
• Stent Placement: Small metal mesh placed in artery to keep it open. Bare metal stents may require anticoagulation for 1 month. Drug-eluting stents reduce inflammation and complications.
• Thrombolytic Therapy: Used when angioplasty unavailable. Medication dissolving clot administered (e.g., Streptokinase, Alteplase). Must be given within 12 hours, ideally within 3 hours. Less effective than angioplasty.
• Coronary Artery Bypass Grafting (CABG): Used for multiple blockages or severe stenosis. Performed when angioplasty fails or in specific post-heart-attack cases.
• Mechanical Heart Support: In severe cases (cardiogenic shock), devices (IABP or ECMO) provide temporary heart support.
• Cardiac Rehabilitation Program: Comprehensive rehabilitation begins before hospital discharge. Includes safe exercise, education, and psychological support. Reduces mortality by 30%.

Lifestyle Changes

• Quit Smoking: Most important step after heart attack. Smoking doubles risk of recurrence. Must quit completely and avoid secondhand smoke.
• Healthy Diet: Eat fruits, vegetables, whole grains, and oily fish (rich in omega-3). Avoid salt, saturated fats, and sugars. Mediterranean diet is ideal.
• Regular Exercise: 150 minutes weekly of regular activity after recovery. Start gradually with walking, progress to swimming and running. Improves cardiac function and reduces weight.
• Weight Management: Ideal weight reduces cardiac strain. Losing 5-10% of body weight improves blood pressure and cholesterol.
• Blood Pressure and Cholesterol Control: Regular monitoring and medication adherence essential for long-term management.
• Stress Management: Yoga, meditation, and relaxation reduce psychological stress. Psychotherapy helps post-attack depression.
• Adequate Sleep: 7-8 hours daily. Poor sleep increases recurrence risk.
• Avoid Alcohol and Drugs: Excessive alcohol and drugs increase heart attack risk and cause arrhythmias.
• Regular Follow-up: Cardiology visits every 3-6 months first year, then annually. Essential for medication assessment and complication monitoring.
• Medication Adherence: Take all prescribed medications regularly without interruption. Non-adherence increases recurrence risk.

• Acute Heart Failure: Heart cannot pump blood efficiently after infarction. Causes pulmonary congestion and severe shortness of breath potentially life-threatening. Requires potent medications and sometimes mechanical support.
• Cardiogenic Shock: Sudden drop in blood pressure and organ perfusion. Occurs after large or multiple infarcts. Mortality rate very high (50%). Requires intensive care and support devices.
• Blood Clots (Thromboembolism): Blood clots may form in heart and travel to brain or limbs causing stroke or acute limb ischemia. Requires long-term anticoagulation therapy.
• Serious Arrhythmias: Ventricular fibrillation (fatal), severe tachycardia or bradycardia. May cause unconsciousness and sudden death. Requires pacemakers or defibrillators.
• Ventricular Wall Rupture: Rare but highly fatal complication. Usually occurs first week post-infarction. Blood leaks into pericardium potentially fatal without urgent surgical repair.
• Mitral Valve Insufficiency: Weakened muscle supporting valve causes blood backflow. Causes shortness of breath and may require valve repair or replacement surgery.
• Pericarditis (Inflammation of Heart Lining): Inflammation of pericardium causing chest pain and fever. Usually resolves with analgesics but may cause fluid accumulation around heart.
• Chronic Ventricular Dysfunction: Infarction may cause permanent weakness in heart contraction even after recovery. May lead to chronic heart failure requiring lifelong medications.

• Blood Pressure Control: Regular monitoring and medication compliance. Ideal blood pressure below 130/80 mmHg. High blood pressure is among the most dangerous risk factors.
• Cholesterol Management: Healthy diet, exercise, and statin medications if needed. LDL cholesterol should be below 100 mg/dL (below 70 for high-risk patients).
• Immediate Smoking Cessation: Smoking increases heart attack risk 3-fold. Quitting reduces risk rapidly within months. Psychological support and medications (e.g., nicotine) can help.
• Maintain Healthy Weight: Body mass index (BMI) should be 18-25. Obesity increases blood pressure, cholesterol, and diabetes risk.
• Regular Physical Activity: 150 minutes weekly of moderate activity or 75 minutes of vigorous activity. Daily walking reduces risk by 30%.
• Balanced Healthy Diet: Increase fruits, vegetables, whole grains, and fish. Reduce salt, saturated fats, and sugars. Mediterranean diet proven effective.
• Diabetes Control: Keep blood sugar controlled (HbA1c < 7%). Uncontrolled diabetes significantly increases risk.
• Reduce Psychological Stress: Chronic stress increases risk. Yoga, meditation, and social relationships important. Seek psychological help when needed.
• Avoid Excessive Alcohol: Moderate drinking may have some benefit, but excess is harmful. Men: no more than 2 drinks daily. Women: one drink daily.
• Regular Checkups: Periodic cardiovascular screening for those over 40 or with risk factors. Early detection of heart and vessel problems can save lives.